A Finicky Mistress

Finally, the long promised information on the '07 zinfandel. I have one barrel of zin from Buck Hill Vineyard which should make about 24-25 cases when it gets bottled in February. It's a big wine with lots of dark fruit flavors and a bright, clean nose. It tastes great and, for a wine hobbyist like me, has been a source of much fun and interest. It has also, at times, been a perplexing beast. As recently as last Friday when we pulled a barrel sample (for research purposes :-)) it was quite worrisome - I thought I had lost the wine. The flavors were off and it simply wasn't showing well at all. Then we tasted it again Sunday and it was better than ever. Wine in barrel can make for a finicky mistress.

But here's the real issue I have been dealing with. It still hasn't finished malolactic conversion (often referred to as malolactic fermentation - MLF). This process, after the initial fermentation which converts the sugar to alcohol, converts malic acid to lactic acid. (Actually it's the conversion of L-malic acid to L-lactic acid and CO2 . . . or C4H6O5 = C3H6O3 + CO2) In lower concentrations, the various compounds produced by MLF are believed to add complexity to the wine's flavor and produce a smoother mouthfeel. When MLF is complete, the wine is considered dry. Well, the zin is still not completely dry - you can tell this by taste when you get a little spritziness on the tip of your tongue. The fact that it still hasn't finished MLF isn't great but isn't necessarily a problem. In fact, when I had a chance to visit one of the greatest zinfandel winemakers in California last July, Mike Officer of Carlisle Winery said he still had several '07 wines that still hadn't finished MLF and he wasn't particularly concerned about it. That was reassuring. (I'm actually drinking some Carlisle zinfandel right now - killer stuff).

Still, you want the wine to finish MLF so the question becomes how do you accomplish this? First, it helps to identify whether it's just going slow or is stuck. In early September, I sent a juice sample for analysis to a lab in Windsor called Vinquiry. The report indicated the malic acid was 144 mg/100 ml. A wine is considered dry when it's 20-30 mg/100 ml. Now it was time to see if we could get that number down. After the barrel had been topped with wine that had finished MLF, we brought the barrel out of the cave and sat it in the sun for a couple days. That's the picture above. On the second day, some juice began to spill out from the bung hole. No big loss of wine - it just showed that the wine had expanded after catching some Sonoma County rays. In other words, we just tried to wake it up so it would finish it's job!!

A week later, I sent another sample to the lab and the results showed the malic acid at 114 mg/100 ml. So, the wine is moving in the right direction which is encouraging. The barrel is now back in the cave and topped up again with press juice. The concern now is to watch out for oxidation - that would be no bueno. At the first sign of oxidation, we'll likely have to hit it with sulphur to protect it but that can slow or stop MLF. Tricky stuff.

So, that's what is up with the '07 zin. It sure helps to have great winemakers like Ed and Eric around to lend a hand or an idea or two. If I hadn't listened to Eric, I would have sulphured the wine already and it might never finish! Since I haven't hit it with sulphur yet, I plan on pulling a couple bottles of barrel samples and bringing them home with me to pour at next month's Zinfest. Should be fun!

Tomorrow we barrel down the '08 zinfandel and the Keefer pinot. As a wine hobbyist, it doesn't get any better. Pics to come!